The present invention generally relates to an apparatus for controlling data traffic across a data subsystem and, in particular, relates to such a subsystem including a plurality of interconnected but independent means for autonomously controlling the flow of data traffic thereacross.
In the general field of modern communications systems, a data communication network is frequently formed by interconnecting a plurality of subsystems, or nodes. Conventionally, each subsystem, or node, is designed to support a prespecified capacity of data traffic. This capacity is normally dependent upon the subsystem hardware and the number of network connections throughout the network. Consequently, in the early stages of the design of a particular subsystem and/or network, one of the more critical issues to be resolved is the data flow capacity requirements of the end users. Without question, subsystems and networks can be designed to handle just about any prespecified data flow capacity. However, a major difficulty lies in the unanticipated increase in data handling requirements of the users after the network is installed.
Hence, when the data handling requirements of a network exceeds the anticipated, or design, levels thereof, a user must either commit to an expensive system redesign or suffer with reduced services.
Another common difficulty of modern subsystems is that, occasionally, during peak use by a small number of subscribers the remaining subscribers are either denied access to the network completely or are subjected to ergonomically unacceptable delays.
Considering the present growth in data transport technology in such fields as computers, microcomputers, electronic mail and so on, the demands upon data communication networks and the subsystems interconnected thereto has escalated far beyond anticipated levels. Such technological growth is anticipated to continue to outstrip the present day communication network designs.
In addition, many individual subscribers to such networks are requiring increased services. Further, numerous services are presently available to supply subscribers with such services as electronic mail, data bases of information, for example, in such fields as finance, law, business, chemistry, and numerous others. Consequently, more and more users are facing the difficulties discussed above.
In light of the above, it is clear that a growing need exists for a subsystem that is both autonomously adaptable to data traffic flow and inexpensively predesigned and adapted for modular expansion.